A defense of the Limit Assumption

1982 ◽  
Vol 42 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Ken Warmbrod
Keyword(s):  
Limit Assumption

Extended stable factor method for the inverse Q-filter

Geophysics ◽  
2020 ◽  
Vol 85 (3) ◽  
pp. T155-T163
Author(s):  
Yong Li ◽  
Gulan Zhang ◽  
Jing Duan ◽  
Chengjie He ◽  
Hao Du ◽  
...  
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Time Frequency ◽  
Stable Factor ◽  
Factor Method ◽  
Data Application ◽  
Two Parameters ◽  
Limit Assumption

The commonly used stable factor methods for the inverse [Formula: see text]-filter achieve good performance in seismic data processing; however, the constant gain-limit assumption in these methods is not associated with the effective frequency band of seismic data and cannot obtain desirable results with high resolution and high signal-to-noise ratio (S/N). Our extended stable factor method for the inverse [Formula: see text]-filter extends these methods by introducing two parameters and constant or self-adaptive gain limit to achieve the desirable high-resolution and high-S/N result. The extended stable factor method for the inverse [Formula: see text]-filter can be implemented in the frequency or time-frequency domain; the latter implementation achieves a higher S/N. Analysis of synthetic signals and field seismic data application illustrate that our method can produce a desirable high-resolution and high-S/N result.

scholarly journals Characteristics investigation on 4.5kV IGBT with partially narrow mesa and split-gate

2021 ◽  
Vol 300 ◽  
pp. 01012
Author(s):  
Xuebing Zhai ◽  
Tong Yang ◽  
Ruliang Zhang ◽  
Jiang Du
Keyword(s):  
Energy Loss ◽  
Contact Resistance ◽  
Short Circuit ◽  
Drift Region ◽  
Switching Loss ◽  
Gate Electrode ◽  
Turn On ◽  
Key Issues ◽  
Electric Filed ◽  
Limit Assumption

Low on-state voltage and low turn-off loss are key issues for IGBT used in HVDC and FACTS. Partial narrow mesa was introduced to improve emitter side contact resistance of IGBT based on Nakagawa limit assumption. However, turn-off loss increases and short circuit sustainability get worse. Split gate separates gate electrode from drift region and reduces gate-collector capacitance to lower turn-off energy loss. Combination partial narrow mesa with split gate can get better gate performance and turn-off characteristics in 4.5kV IGBT. Simulated results with TCAD show proposed models improves switching loss and gate reliability. By adjusting split gap electric filed, split gate shape has an important effect on turn-on characteristics.

scholarly journals The Limit Assumption

2017 ◽  
Vol 10 (18) ◽  
pp. 1
Author(s):  
Stefan Kaufmann
Keyword(s):  
Limit Assumption

Bessel Composite Function of the Third Order and First Kind Solution to Damped Wave Conduction and Relaxation

2008 ◽  
Author(s):  
Kal Renganathan Sharma
Keyword(s):  
Analytical Solutions ◽  
Spherical Coordinates ◽  
Relaxation Equation ◽  
Third Order ◽  
Composite Function ◽  
The Third ◽  
Relativistic Transformation ◽  
Approximate Analytical Solutions ◽  
Composite Solution ◽  
Limit Assumption

The damped wave conduction and relaxation equation in three dimenions in spherical coordinates was solved for by using the relativistic transformation. Approximate analytical solutions were obtained in the creeping transfer limit in spherical infinite coordinates. The solution consist of three regimes. A inertial zero transfer regime. A second regime that is characterized by the Bessel composite function of the third order and first kind. The third regime is characterized by the modified composite function of the third order and first kind. Without the creeping transfer limit assumption the order of the Bessel composite solution can be seen to be 7/2.

EXPRESSIBLE SEMANTICS FOR EXPRESSIBLE COUNTERFACTUALS

2010 ◽  
Vol 4 (1) ◽  
pp. 63-80
Author(s):  
EMMANUEL CHEMLA
Keyword(s):  
Possible Worlds ◽  
Truth Values ◽  
Restricted Version ◽  
Ordering Semantics ◽  
Premise Semantics ◽  
Cast Doubt ◽  
Limit Assumption ◽  
Equivalence Result

Lewis (1981) showed the equivalence between two dominant semantic frameworks for counterfactuals: ordering semantics, which relies on orders between possible worlds, and premise semantics, which relies on sets of propositions (so-called ordering sources). I define a natural, restricted version of premise semantics, expressible premise semantics, which is based on ordering sources containing only expressible propositions. First, I extend Lewis’ (1981) equivalence result to expressible premise semantics and some corresponding expressible version of ordering semantics. Second, I show that expressible semantics are strictly less powerful than their nonexpressible counterparts, even when attention is restricted to the truth values of expressible counterfactuals. Assuming that the expressibility constraint is natural for premise semantics, this result breaks the equivalence between ordering semantics and (expressible) premise semantics. Finally, I show that these results cast doubt on various desirable conjectures, and in particular on a particular defense of the so-called limit assumption.

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